This invention relates generally to cellular cushions, and more particularly, to methods and apparatus for fabricating cellular cushions.
Individuals who are confined to wheelchairs may run the risk of tissue breakdown and the development of pressure sores, which are extremely dangerous and difficult to cure. More specifically, as such individuals are primarily in a seated position for extended periods of time, their weight may be concentrated in the bonier portions of the individual's buttocks. Over time, blood flow to such areas may decrease, causing tissue to break down in these areas.
To facilitate reducing the weight concentration of such individuals, at least some users seated in at least some known wheelchairs use cellular cushions facilitate distributing the individual's weight over a larger area and across the individual's buttocks, and to facilitate decreasing their weight concentration in smaller areas. At least some known cellular cushions include a plurality of hollow fluid-filled cells which project upwardly from a common base. More specifically, because the plurality of air-filled cells are coupled in flow communication through the base, the air within such cells is at the same pressure throughout the plurality of cells, and as such, each cell exerts the same pressure against an individual's buttocks.
However, although such cushions do facilitate distributing the weight across the individuals buttocks, the plurality of cells provide less stability to the seated individual in comparison to a substantially planar seating surface. To facilitate increasing the stability of the user, at least some known cellular cushions are divided into isolated zones of cells, wherein the cells of each zone are only in flow communication with the cells within their zone. By varying the pressure between the isolated zones, the user may be able to increase their stability on the cellular cushion depending on the physical condition of the user. More specifically, the isolated zones may provide only slightly more stability to those users that lack muscular strength in their pelvis and/or thigh regions. Furthermore, such cellular cushions may not provide any additional stability to users that have a skeletal deformity, such as a pelvic obliquity. More specifically, within at least some known zoned cushions, such cushions may bottom out to provide little or no cushioning to a user having a skeletal deformity.